The present invention relates to a cutting insert for chipforming machining of workpieces of metal, and in particular to triangular, square, rhombic, rhomboidic or other forms of indexable cutting inserts used with toolholders. The basic form of such cutting inserts comprises two opposed top and bottom surfaces and a peripheral wall extending therebetween. The cutting edges are formed by the transition between the top surface and the peripheral wall of the insert. The top surface of the insert is a chip face or such a surface which is in contact with the formed chip at the cutting operation, and the peripheral wall being a clearance face in relation to the workpiece.
It is generally desirable that these inserts should have a geometry that will minimize the power required in the metalworking operations by controlling the geometry of the chips produced and that the insert chip control geometry should be capable of controlling chips over a wide range of parameters such as depth of cut or feed rate.
Typical prior art inserts known to applicant are disclosed in U.S. Pat. Nos. 3,815,192 and 3,973,308. In the insert according to the former patent, a plurality of projections are spaced so as to define chip curling zones therebetween, and in the latter patent, a plurality of notches were so formed that the chip could pass or slide over them without being broken or substantially deformed.
The insert of the present invention has a chip face that is modified to have a more favorable form in regard to the cutting forces and to wear of the cutting tool.